Fundamentals of Electric Circuits MCQs (Part-5)

What happens to the total resistance in a series circuit if the resistance of one resistor increases?

A The total resistance decreases
B The total resistance increases
C The total resistance remains the same
D The current increases

What is the total voltage across the components in a parallel circuit?

A It is divided equally among the components
B It is the same across all components
C It is the sum of individual voltages
D It is zero

What is the formula for calculating the total resistance in a parallel circuit with two resistors, R1 and R2?

A R_total = R1 + R2
B R_total = 1 / (1/R1 + 1/R2)
C R_total = R1 * R2
D R_total = (R1 + R2) / 2

What does Kirchhoff’s Current Law (KCL) state?

A The sum of voltages around a closed loop equals zero
B The sum of currents entering a junction equals the sum of currents leaving the junction
C The current in a circuit is constant
D The voltage across resistors is constant

What happens to the current in a series circuit if the total resistance is increased?

A The current decreases
B The current increases
C The current stays the same
D The current becomes zero

What is the relationship between current and voltage in a resistive circuit according to Ohm’s Law?

A Voltage is inversely proportional to current
B Voltage is directly proportional to current
C Voltage is constant
D Current is constant

How is the total power in an electrical circuit calculated?

A Power = Voltage × Resistance
B Power = Current × Voltage
C Power = Voltage / Current
D Power = Current × Resistance

What is the main function of an inductor in an AC circuit?

A To store energy in an electric field
B To store energy in a magnetic field
C To resist changes in voltage
D To convert AC to DC

What is the unit of reactance in an AC circuit?

A Volt
B Ampere
C Ohm
D Henry

What is the primary purpose of a capacitor in an electrical circuit?

A To increase current flow
B To store electrical energy in an electric field
C To filter out noise
D To store electrical energy in a magnetic field

What happens to the current in a parallel circuit when more resistors are added?

A The current decreases
B The current increases
C The current stays the same
D The current becomes zero

What is the unit of inductance?

A Watt
B Volt
C Henry
D Ampere

What is the main function of a transformer in an electrical system?

A To store electrical energy
B To increase or decrease voltage
C To control current flow
D To filter out noise

What happens in a DC circuit when the power factor is 1?

A The circuit is inefficient
B The circuit uses all power effectively
C The current is zero
D The voltage is equal to current

What is the unit of reactance in an AC circuit?

A Watt
B Ohm
C Volt
D Ampere

What is the main function of a feedback mechanism in an electrical circuit?

A To store energy
B To stabilize the circuit’s performance
C To increase power
D To decrease current flow

What happens to the voltage in a series circuit if the total resistance increases?

A The voltage decreases
B The voltage increases
C The voltage remains the same
D The voltage becomes zero

What is the phase difference between current and voltage in a purely inductive AC circuit?

A 0 degrees
B 45 degrees
C 90 degrees (current lags voltage)
D 180 degrees

What happens in an electrical circuit when the power factor is less than 1?

A The circuit uses all power efficiently
B Some of the power is wasted as reactive power
C The current is zero
D The voltage is equal to current

What is the primary purpose of a diode in an electrical circuit?

A To amplify the signal
B To allow current to flow in only one direction
C To resist current flow
D To store electrical energy